77640000 has 140 divisors (see below), whose sum is σ = 257092704. Its totient is φ = 20672000.

The previous prime is 77639999. The next prime is 77640001. The reversal of 77640000 is 4677.

It is an interprime number because it is at equal distance from previous prime (77639999) and next prime (77640001).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77640001) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 119677 + ... + 120323.

Almost surely, 2^77640000 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77640000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128546352).

77640000 is an abundant number, since it is smaller than the sum of its proper divisors (179452704).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77640000 is an equidigital number, since it uses as much as digits as its factorization.

77640000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 682 (or 657 counting only the distinct ones).

The product of its (nonzero) digits is 1176, while the sum is 24.

The square root of 77640000 is about 8811.3563087643. The cubic root of 77640000 is about 426.6075221837.

Adding to 77640000 its reverse (4677), we get a palindrome (77644677).

The spelling of 77640000 in words is "seventy-seven million, six hundred forty thousand".